which

1 : being what one or ones out of a group —used as an interrogative which tie should I wearkept a record of which employees took their vacations in July

2 : whichever it will not fit, turn it which way you like

3 —used as a function word to introduce a nonrestrictive relative clause and to modify a noun in that clause and to refer together with that noun to a word or word group in a preceding clause or to an entire preceding clause or sentence or longer unit of discourse in German, which language might … have been the medium of transmission— Thomas Pylesthat this city is a rebellious city …  : for which cause was this city destroyed — Ezra 4:15 (King James Version)

1 : what one or ones out of a group —used as an interrogative which of those houses do you live inwhich of you want tea and which want lemonadehe is swimming or canoeing, I don't know which

2 : whichever take which you like

3 —used as a function word to introduce a relative clause —used in any grammatical relation except that of a possessive —used especially in reference to animals, inanimate objects, groups, or ideas the bonds which represent the debt— G. B. Robinsonthe Samnite tribes, which settled south and southeast of Rome— Ernst Pulgram —used freely in reference to persons as recently as the 17th century our Father which art in heaven — Matthew 6:9 (King James Version), and still occasionally so used but usually with some implication of emphasis on the function or role of the person rather than on the person as such chiefly they wanted husbands, which they got easily— Lynn White —used by speakers on all educational levels and by many reputable writers, though disapproved by some grammarians, in reference to an idea expressed by a word or group of words that is not necessarily a noun or noun phrase he resigned that post, after which he engaged in ranching — Current Biography